Answer
The abdominal aorta starts at the level of the intervertebral disc, between the fourth and fifth thoracic vertebrae (T4 and T5).
Work Step by Step
The descending aorta passes downard behind the heart, travels through the thoracic cavity, and then enters the abdominal cavity, after piercing the diaphragm Above the diaphragm the descending aorta is called the thoracic aorta; below the diaphragm, it becomes the abdominal aorta.
